1. Field of the Invention
The present invention relates to a portable terminal system equipped with a portable terminal device such as a portable phone (cellular phone) or the like, and an external speaker for converting electrical signals from the portable terminal device to sound wave signals.
2. Description of Related Art
Various portable terminal devices represented by cellular phones have been hitherto required to be enhanced in the sound quality of voices from communication partners and call receiving sounds and also more miniaturized in size. In order to miniaturize a portable terminal device, it is required to reduce the size and thickness of a built-in speaker of the portable terminal device.
As the reduction in size and thickness of the built-in speaker is promoted, the sound quality of the voices of communication partners and the call receiving sounds is more degraded, and also the sound volume is more lowered. Besides, the requirement of miniaturizing the portable terminal device makes it difficult to increase of the size of the built-in speaker. Therefore, there is known a technique of securing an external speaker to a portable terminal device without installing the built-in speaker in the portable terminal device.
According to this technique, the external speaker is secured to the portable terminal device, and thus it is required to perform wire connection to a signal side terminal and a ground side terminal in order to connect the external speaker and the portable terminal device to each other. Further, an enclosure for the external speaker is needed to be newly provided. As a result, there is a case that a portable terminal system having a portable terminal device and an external speaker must be designed in a large size.